This invention relates to kick-out switches and buzzers such as used in connection with washing machines to provide protection against operation with an unbalanced load in the tub. During the operation of a washing machine, it is possible for the clothes in the tub to become so bunched together as to seriously unbalance the tub and cause it to wobble excessively as it spins during the spin-dry portion of the operating cycle. Under such unbalanced conditions, it is necessary to automatically turn the washing machine motor off and to sound an audible alarm which indicates that the washing machine has been turned off due to an unbalanced condition. In the past, these functions have been performed by kick-out switches and buzzers.
The prior art kick-out switches and buzzers have utilized a buzzer structure including a coil which was connected in parallel with a pair of normally closed contacts. The coil and normally closed contacts were connected in series with the AC power input to the washing machine motor. As long as the contacts remained closed, the motor operated normally and the buzzer was silent due to the short circuit provided by the normally closed contacts across its coil. When the contacts were open, however, this connected the coil in series with the washing machine motor, thereby turning the motor off, and simultaneously energizing the buzzer. A kick- out actuating arm was connected between the washing machine tub and the switch contacts to open the contacts when a predetermined amplitude of wobble was present in the tub. After the kick-out switch and buzzer were actuated, they could be reset to their initial condition by turning the washing machine off and then turning it back on again. This de-energized the coil and allowed the normally closed contacts to close again.
But although the prior art kick-out switches and buzzers performed their intended function, they had several serious drawbacks. In the first place, due to the fact that they had to respond to a predetermined amplitude of movement, these prior art kick-out switches and buzzers involved relatively precise dimensions and tended to be relatively expensive. They also tended to be relatively comples and cumbersome in structure and relatively difficult to assemble.